Electrical-impulse-transmitting device.



I J. ERIGKSON.

ELECTRICAL IMPULS RAN TING DEVICE.

APPLICATION D'A 0,1906.

I 909,382. Patented Jan. 12,1909.

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, J. ERIGKSON. ELECTRICAL IMPULSE TRANSMITTING DEVICE.

APPLICATION FILED AUG. 20, 1906.

Patented Jan. 12, 1909.

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J. ERIGKS ON.

ELECTRICAL IMPULSE TRANSMITTING DEVICE.

APPLIOATION FILED AUG. 20, 1906.

909,382. Patented Jm,12,1909.

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mvirnn STATES PATENT JOHN ERICKSON, OF CHICAGO, ILLINOIS, ASSIGNOR, BY MESNE ASSIGJH XTS. TO FIRST TRUST AND SAVIRGS BANK, TRUSTEE, OF ,CHI CAGO, ILLINOIS.-

ELEC'IBICAL-IMPU'LSIB-TRANSMITTING DEVICE.

Specification of Letters Patent.

Patented Jan. 12, 1909.

Application filed August 20, 1 906. Qerial N 0. 331,304.

to transmit a separate group of impulses for ,each digit of any called telephone number, as, for example, the rotatable dials or aperture'd disks which are employed in certain automatic telephone systems and which transmit the electrical impulses after being released and allowed to rotate back to normal position.

Prior to my invention it has been found that calling subscribers will some times attempt to force or accelerate the backward rotation of the dial or apertured disk, and this, of course, tends to produce uncertainty in the transmission of electrical impulses resulting from the rotation of the dial to normal position, with the. further result that the automatic switches at the exchange or central station will not always operate in the desired manner.

- The object of my invention is, therefore, the provision of an improved calling device or electrical in1pulse-transmitter of such character that itsrotatable dial or apertured disk cannot be forced or rotated backward any faster than the speed or rate of motion produced by the spring which furnishes the power for restoring the dial or disk to its normal positionthat is to say, after it has been partially rotated in a forward direction and then released by the calling subscriber. With such an arrangement it is obvious that the backward rotation of the dial or apertured disk is always at the required rate of speed, and is never'faster than the motion produced by the spring which furnishes the power for restoring it to normal position, even though the calling subscriber reverses his pressure on the dial and attempts to force or accelerate its backwardor return rotation.

In the accompanying drawings, Figure 1 is a front elevation of an electrical impulsetransmitter or calling device embodying the principles of my invention, certain portions thereof being broken away for convenience of illustration, and the same being shown applied to the telephone, set of an automatic exchange. Fig. 21s a view similar to Fig. 1, showing another form of my invention. Fig. 3 illustrates the mechanism of Fig. 1,

with the dial removed. Fig. 4 is a rear elevation of the mechanism shown in Figs. 1 and 3. Fig. 5 is a sectional view showing the toothed impulse wheel, and the springs which are engaged by the latter, of the mechaiiism shown in Fig. 1. Figs. 6 toll, inclusive, illustrate different positions of the impulse springs and toothed wheel of the mechanism shown in either Figs. 1 or and show how the impulses are transmitted in the well-known manner. The construction shown in Figs. 3, .4 and may be employed for, the mechanism shown in Fig. 2, as will be readily understood.

In Fig. 1. the rotatable dial or apertured disk A is of the usual or well known form and character, but is loosely mounted upon the central shaft or arbor B. .The inner disk C is, however. rigidly secured to the said shaft or arbor. It will beunderstood that this shaft or arbor is mounted in suitable bearings, and that its rotation in a back ward direction is produced by a suitable spring within the telephone casing D. This inner disk C is provided with a peripheral notch 12. As shown, the rotatable dial'or apertnred disk A is provided on its inner surface with a pivoted dog E having its end portion adapted to engage the notch 0. The said dog is also provided with a hook portion 0 adapted to engage the ratchet-teeth on the inner edge of the curved rack F. It will be seen that this curved rack extends a little over half way around the disk C, and that its teeth are close to the periphery of the latter. When the parts are in their normal positions, the 'tension of the spring on .the disk C is in a counter-clockwise direction, and is communicated to the dial or disk A through the medium of the dog E, this pressure, of course, tending to keep the said dog in engagement with the notch c. WVhe'n the device is used for calling, and'when the dial A is partially rotated, such forward rotation is communicated through the said dog to the disk C, with the result that the said shaft or arbor is rotated in a clockwise direction,.and with the further result that the said spring is partially wound up. As soon as the dial is released by the calling sub-. scriber, in the usual manner, the tension of the spring is then immediately communicatedthrough the disk 0 and thedog E to the dial A, with the result that the pressure of the spring is sufiicient to keep'the said dog in engagement'with' the notch 0, thus preventing the hook portion 0 from engaging any of the teeth on the rack F. Suppose, howeverf that the calling subscriber should fail to release the dial A, and after rotating it in a forward or clockwise direction to the proper, extent, should-attempt to force or accelerate its backward or counter-clockwise rotation. In such case the dialor apertured disk A would speed up and run ahead of the disk C, allowing the dog E to dropout of thenotch c, causing the hook portion e of the dog to immediately engage a ratchettooth on the rack F. This will hold the dial at a point in its backward direction, and the subscriber must then release the dial in order to allow it to continue its backward rota tion. In this way an accelerated or unduly high speed ofthe dial andof the impulsetransmitting mechanism is practically im-' possible;

a In Fig. 2 the construction is the same as that shown in F ig. l, with the exception that the dog G is provided with a pivoted brake-shoe 9 adapted to engage the smooth inner edge of the curved member H, which latter corresponds to the rack FL With this arrangement an attempt to force or accelerate the backward rotation of the'dial I will cause the dog G to become disengag d from the disk J, and will cause the brakeshoe ,9 to engage the curved member H, thereby positively retarding the backward rotation of the dial. It will be understood,

of course, that the dogs E and G can be provided with springs tending to throw 1 themout of engagement with the disks C and J should the speed of the dial increase or become faster than the backward rotation of the inner disk-that is to say, the disk engaged by the dog.

Figs. 3 to 11. inclusive, illustrate the wellknown form of subscribers calling mechan-' ism, in connection with which I have elected to describe my invention. Referring to Fig. 5 it will be seen that the impulse wheel K is mounted on the shaft B, and is adapted to operate the impulse springs Land M relativelyto the ground post'N, in the wellknown manner.- Referring to Fig. 3 it will be seen that thespring O operates like a clock spring, and serves to give the impulse wheel and dial a backward rotation. As this mechanism is common and Well-known, no further description is necessary.

1 With either arrangement the backward change.

rotation of the dial or apertured disk is retarded or checked as soon as an attempt is made to force it above a certain speed. Uonsequently, the mechanism of the impulse-x transmitter or calling device can be 'carefully adjusted with a view to having the electrical impulses transmitted in the proper manner, and the user of the telephone, if

the device to be usedin an, automatic tele-' phone system, cannot" then; interfere ith the proper transmlsison of the electrical 1mpulses at the rate required for properly opcrating the automatic switches at the exlt will be seen that the device, in either of the two forms shown, is adapted to prevent forcing or undue, acceleration of the dial. The .Iorce of the sprin'g'which returns the impulse wheel is, however,.not opposed or retarded by the said device, so that the positive locking of the dial=against forcing or undue acceleration is dependent'upona backward rotatlon thereof. I 'lhe notch 0 in the wheel C, or the corresponding notch in the wheel J, constitutes a means for'preventing the dial lock or retarding device from interfering with the .naturalbackward rotation of the impulse wheel when the subscriber releases or withdraws his-hand from 4 the dial; In other words, the said dial-lock or retarding device is inoperative to oppose or retard the normal propelling.action-of the spring by which the impulse Wheel is rotated.

What I claim as my invention is 1. In automatic telephony, the combination of electrical impulse-transmitting means, a rotatable dial for operating'said means, adapted to cause the transmission of electrical impulses upon being released and allowed to return to normal position, and a retarding device for resisting the backward rotation of the dial only when 'an attempt is made to manually force the dial to its normal posit-ion.

2. In automatic telephony, the combination of electrical impulse-transmitting means, a rotatable dial for operating said means, a spring for returning the dial to its normalposition, and means for positively retarding the backward rotation of the. dial only when an attempt is made to manually "rotate the dial faster thanthe speed insured by said spring.

3. In automatic telephony, a rotatable dial provided with a retarding device by which its backward rotation is positively resisted only when an attempt ismade to manually force'it to normal position. v

4-. In automatic telephony, a rotatable calling dial provided on its inner surtem witha pivoted dog, a rotatable member having a notch adapted to be engaged bythe' end of said dog. said dog thereby compelling said rotatable member to rotate in unison with the forward rotation of said dial,

impulses said dog adapted to disengage from said notch when the backward rotation of the dial is faster than the corresponding rotation of said rotatable ember, a curved stationary member, and means on said dog for engaging said curved retard or positively resist the backward rotation of the dial when an attempt is made to manually force the latter to its normal position.

'5. In automatic telephony, the combination of a rotatable dial or apertured disk, spring means for returning the dial to normal position, means for transmitting electrical impulses when the dial rotates to normal position, an inner rotatable disk p='ovided with a peripheral notch, a dog pivoted on the inner side of said dial and adapted to engage said notch. said dog compelling the inner disk to rotate in unison with the forward rotation of the dial, but said dog adapted to disengage from said notch as soon as the backward rotation of the dial becomes faster than the corresponding rotation of the inner disk, a curved member extending a suitable distance around the periphery of the said inner disk, and means on said dog for engaging the inner edge of said curved member to retard or positively resist the backward rotation of the dial when an attempt is made to force the latter to normal position.

6. A subscribers calling device for. auto matic telephone systems, comprising a rotatable calling dial for transmitting the electrical impulses, and a dial lock for preventing a subscriber from forcing or accelerating the backward or return rotation, of the dial, operative to positively lock the dial only upon undue acceleration thereof.

7. A calling device for automatic telephone systems, comprising a hand-operated dial-controlled mechanism for transmitting the electrical impulses, and a dial lock for preventing the operator from forcing or accelerating the motion of the dial while the are being transmitted, operative to positively-"lock the dial only upon undue acceleration thereof. i

8. In a telephone system, an impulse wheel, a shaft for said wheel. a calling dial loose on said shaft and provided with aseries of holes, means by which said dial is operative to rotate the shaft in one direction only, a stop to limit the rotation of the dial in accordance with the hole selected thereon, and a spring for rotating the shaft in the opposite direction. I

9. In a telephone system, an impulse wheel rotatable in a back and forth manner, a rotatable calling dial, means by which the dial is operative to rotate the wheel in one direction only, a stop for variably limiting the rotation of the dial, and a spring for rotating the wheel in the opposite direction.

stationary member to 10. In a telephone system, an impulsetransmittingdevice, a rotatable calling dial for operating said device, means for preventing forcing or undue acceleration of the dial, and a spring for returning the dial to normal position, said means being inoperative to resist or retard the propelling action of said spring.

11. In a telephone system, arotatable calling dial, a device for transmitting impulses by the backward rotation of said dial, means for preventing forcing or undue acceleration of the dial during its backward rotation, and a spring for returning the dial to normal position, said means being inoperative to resist or retard the propelling action of said spring.

12. In a telephone system, an impulse mechanism, means for preventing forcing or undue acceleration of said mechanism, while the impulses are being transmitted, and a spring for restoring said mechanism to normal condition, said means being inoperative to resist or retard the action of said spring. 7

13. In a telephone system, a rotatable calling element, means for preventing forcing or undue acceleration of said element, while the calling impulses are bein sent, and an operatin spring which is free from the action of said means.

14:. A subscribers calling mechanism pro vided with impulse-transmitting devices including a spring for propelling the same to normal position to transmit the impulses, and means operative to prevent forcing or acceleration of the said mechanism during the transmission of the impulses, but inoperative to affect the action of said spring.

15. A telephone calling mechanism comprising a rotary dial having a series of numeral holes, a rotary impulse-transmitting device, means for preventing forced backward rotation of said dial after the same has been rotated forward in making the call, a spring for propelling said device, and a stop for variably limiting the rotation of said dial, said means being inoperative to afiect the action of said spring. 7 16. A telephone calling mechanism comprising a rotary dial having a series of holes, a spring for propelling said mechanism to t ansmit the call, means operative to prevent backward rotation of said dial by hand, but inoperative to resist the propelling action of said spring, and a stop acting to limit the forward rotation of the dial in accordance with the hole selected thereon.

Signed by me at Chicago, Cook county. Illinois, this 16th day of August, 1906.

JOHN ERICKSON.

Witnesses: i I EDWARD D. FALES,

- BERNARD D. WILLIS. 

